// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_COMPILER_SIMD_SCALAR_LOWERING_H_
#define V8_COMPILER_SIMD_SCALAR_LOWERING_H_

#include "src/compiler/common-operator.h"
#include "src/compiler/graph.h"
#include "src/compiler/machine-graph.h"
#include "src/compiler/machine-operator.h"
#include "src/compiler/node-marker.h"
#include "src/zone/zone-containers.h"

namespace v8 {
namespace internal {

    template <typename T>
    class Signature;

    namespace compiler {

        class SimdScalarLowering {
        public:
            SimdScalarLowering(MachineGraph* mcgraph,
                Signature<MachineRepresentation>* signature);

            void LowerGraph();

            int GetParameterCountAfterLowering();

        private:
            enum class State : uint8_t { kUnvisited,
                kOnStack,
                kVisited };

            enum class SimdType : uint8_t { kFloat32x4,
                kInt32x4,
                kInt16x8,
                kInt8x16 };

#if defined(V8_TARGET_BIG_ENDIAN)
            static constexpr int kLaneOffsets[16] = { 15, 14, 13, 12, 11, 10, 9, 8,
                7, 6, 5, 4, 3, 2, 1, 0 };
#else
            static constexpr int kLaneOffsets[16] = { 0, 1, 2, 3, 4, 5, 6, 7,
                8, 9, 10, 11, 12, 13, 14, 15 };
#endif
            struct Replacement {
                Node** node = nullptr;
                SimdType type; // represents output type
                int num_replacements = 0;
            };

            struct NodeState {
                Node* node;
                int input_index;
            };

            Zone* zone() const { return mcgraph_->zone(); }
            Graph* graph() const { return mcgraph_->graph(); }
            MachineOperatorBuilder* machine() const { return mcgraph_->machine(); }
            CommonOperatorBuilder* common() const { return mcgraph_->common(); }
            Signature<MachineRepresentation>* signature() const { return signature_; }

            void LowerNode(Node* node);
            bool DefaultLowering(Node* node);

            int NumLanes(SimdType type);
            void ReplaceNode(Node* old, Node** new_nodes, int count);
            bool HasReplacement(size_t index, Node* node);
            Node** GetReplacements(Node* node);
            int ReplacementCount(Node* node);
            void Float32ToInt32(Node** replacements, Node** result);
            void Int32ToFloat32(Node** replacements, Node** result);
            template <typename T>
            void Int32ToSmallerInt(Node** replacements, Node** result);
            template <typename T>
            void SmallerIntToInt32(Node** replacements, Node** result);
            Node** GetReplacementsWithType(Node* node, SimdType type);
            SimdType ReplacementType(Node* node);
            void PreparePhiReplacement(Node* phi);
            void SetLoweredType(Node* node, Node* output);
            void GetIndexNodes(Node* index, Node** new_indices, SimdType type);
            void LowerLoadOp(Node* node, SimdType type);
            void LowerStoreOp(Node* node);
            void LowerBinaryOp(Node* node, SimdType input_rep_type, const Operator* op,
                bool not_horizontal = true);
            void LowerCompareOp(Node* node, SimdType input_rep_type, const Operator* op,
                bool invert_inputs = false);
            Node* FixUpperBits(Node* input, int32_t shift);
            void LowerBinaryOpForSmallInt(Node* node, SimdType input_rep_type,
                const Operator* op, bool not_horizontal = true);
            Node* Mask(Node* input, int32_t mask);
            void LowerSaturateBinaryOp(Node* node, SimdType input_rep_type,
                const Operator* op, bool is_signed);
            void LowerUnaryOp(Node* node, SimdType input_rep_type, const Operator* op);
            void LowerIntMinMax(Node* node, const Operator* op, bool is_max,
                SimdType type);
            void LowerConvertFromFloat(Node* node, bool is_signed);
            void LowerConvertFromInt(Node* node, SimdType input_rep_type,
                SimdType output_rep_type, bool is_signed,
                int start_index);
            void LowerPack(Node* node, SimdType input_rep_type, SimdType output_rep_type,
                bool is_signed);
            void LowerShiftOp(Node* node, SimdType type);
            Node* BuildF64Trunc(Node* input);
            void LowerNotEqual(Node* node, SimdType input_rep_type, const Operator* op);
            MachineType MachineTypeFrom(SimdType simdType);

            MachineGraph* const mcgraph_;
            NodeMarker<State> state_;
            ZoneDeque<NodeState> stack_;
            Replacement* replacements_;
            Signature<MachineRepresentation>* signature_;
            Node* placeholder_;
            int parameter_count_after_lowering_;
        };

    } // namespace compiler
} // namespace internal
} // namespace v8

#endif // V8_COMPILER_SIMD_SCALAR_LOWERING_H_
